Antonyms of adj two-party

1 sense of two-party

Sense 1
bipartisan, bipartizan, two-party, two-way -- (supported by both sides; "a two-way treaty")

INDIRECT (VIA nonpartisan) -> partisan, partizan -- (devoted to a cause or party)

Similarity of adj two-party

1 sense of two-party

Sense 1
bipartisan, bipartizan, two-party, two-way -- (supported by both sides; "a two-way treaty")
       => nonpartisan (vs. partisan), nonpartizan -- (free from party affiliation or bias)